Intel Second Generation Core i7 3820 Review

Testing:

Testing the Second Generation Intel Core i7 3820 Sandy Bridge Extreme will involve running it and its comparison products through OCC's test suite of benchmarks, which include both synthetic benchmarks and real-world applications. The gaming tests will also consist of both synthetic benchmarks and actual game play, in which we can see if similarly-prepared setups offer any performance advantages. The system will receive a fully updated, fresh install of Windows 7 Professional 64-bit edition, in addition to the latest drivers for each board and latest AMD Catalyst drivers for the XFX HD 6970. To ensure as few variables as possible, all hardware will be tested at their stock speeds, timings, voltages, and latencies, unless otherwise stated. Turbo Boost will be disabled on all processors to make a fair comparison without skewing the results.

Overclocking:

Overclocked settings:

Processor: Intel Core i7 3820 – 5025 MHz (126.6 x 40)

When it comes to overclocking the Second Generation Core i7 3820, there are a few limitations, as it is a partially unlocked processor; not quite K spec, but not a base model either. By partially unlocking the chip, Intel has still catered to the enthusiast, though not giving up the reigns totally. The Core i7 3820 has a maximum clock multiplier of 43x. It means that the most you will see with the 100 MHz bclock is 4300 MHz or just a mere 400 MHz above the Turbo Boosted speeds delivered from factory. That, of course, will not do; not for an Enthusiast-grade platform. The 2600K and 2700K are able to hit well above this number for a comparable cost. On the Socket LGA 2011 X79 platform, Intel has given enthusiasts a tool that allows the CPU bclock to be adjusted up via a series of Gear Ratios that start at 100 MHz, all the way to 250 MHz. To get the most out of the Core i7 3820, I will have to use the bclock, Gear Ratios, and adjustments of the multiplier to levels lower than 43x. In my first run, I intended to see what kind of bclock tolerance the chip had. Eventually, I was able to push the bclock from 100 MHz to 107 MHz; a pretty decent bclock increase that allowed the chip to scale to 4.6 GHz. Again, this was not enough of a clock, as my 2600K does that easily. Next up was the 125 MHz Gear Ratio and multiplier adjustment; this moved the needle quite a bit higher to 5.0 GHz. Further bclock tuning up to 125.625 MHz gained a prime stable 5025 MHz clock speed from the chip. Further tuning of the bclock could have raised the bar even higher, though without the benefit of long term stability. Nonetheless, it was capable of running the entire benchmark suite at 5.1 GHz. Voltage tuning and enhanced cooling was needed to get these clock speeds, but nothing more extreme than what most would endeavour to use.

If overclocking is not in your future, Intel's Turbo Boost 2 technology is used to boost the speed of the processor under differing usage conditions. Low load situations with one or two cores active will see a boost of up to 600 MHz over the base clock speeds of 3300 MHz, or a total of 3900 MHz. With all cores active, you can expect a boost of up to 300 MHz for a total of 3600 MHz when fully loaded. Each of these scenarios offer a nice boost in clock speed, with really no effort, as the BIOS setting is enabled by default, allowing the end user the ability to overclock without really overclocking; Intel simply does it for you.

Maximum Core Clock Speed:

Each CPU has been tested for stability at the listed overclocked speeds. These clock speeds will represent the clock speed used in the overclocked scores for the testing.